Structure and Electronic Properties of Edge-Functionalized Armchair Boron Nitride Nanoribbons

• Published in: Journal of physical chemistry. C Vol. 116; no. 29; pp. 15675 - 15681
• Main Authors: Lopez-Bezanilla, Alejandro, Huang, Jingsong, Terrones, Humberto, Sumpter, Bobby G
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 26.07.2012
• Subjects: 08 HYDROGEN; AMPLITUDES; ATOMS; BOND LENGTHS; BORON NITRIDES; CHAINS; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; FUNCTIONALS; HYDROGEN; Methods of electronic structure calculations; PEROXIDES; Physics; Band structure; Hydrogen neutral atoms; Density of states; Electronic properties; Semiconductor materials; Theoretical study; Boron nitride; Ripples; Armchair nanotube; Bond lengths; Energy gap; Unit cell; Chemical modification; Electronic structure; Acceptor center; Functionalization; Hydrogen bonds; Quantum mechanics; Density functional method; Quantum theory
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp3036583

We report a quantum mechanical description based on the density functional theory of the structures and electronic properties of armchair boron nitride nanoribbons (BNNRs) edge-terminated with O atoms and OH groups. The O edge termination was found to give a peroxide-like structure that is nonmagnetic and semiconducting with a bandgap of E g = 2.8 eV. The O-terminated BNNR ribbon was stabilized by the reduction of the peroxide groups with H atoms leading to a polyol-like structure. The two chains of hydrogen bonds created along the edges lead to alternating 5- and 7-membered rings and cause the ribbon to become nonplanar with rippled edges. Three configurations of different ripple periods and amplitudes were found with energy differences up to 2 eV per unit cell but with virtually the same bandgap of E g = 4.2 eV. The hydrogen bond mediated ripples are characterized through the lone pair orbitals showing a local σ–π separation and a pair of “rabbit-ears” on the acceptor O atoms in 5- and 7-membered rings respectively dictated by the hydrogen bond lengths. Energy bands and total and projected density of states are discussed for both functionalizations to show their effects on altering the electronic properties of armchair BNNRs.